A brake controller is usually an original equipment manufacturer or aftermarket-installed device or module. It is mounted to the tow vehicle's driver's-side dashboard area, and engages a trailer's electrical braking system either time delayed, or in proportion to the tow vehicle's brake engagement when slowing down or coming to a halt. A brake controller is not needed with a trailer surge braking system unless using modern electric over hydraulic devices. The trailer in this case usually has either electric friction brakes or electric-hydraulic trailer brake actuators. Most basic brake controllers will generally have a plus-minus gain adjustment. The tow vehicle operator sets the gain as high as possible but without the trailer brakes locking up after making a few test stops. The heavier the trailer, the higher the gain adjustment is set and therefore the less chances of wheel lock-up. A wide range of trailers contain trailer brakes (for example, larger boat trailers, horse trailers, covered utility trailers, enclosed trailers, travel trailers including small 10 ft and longer tent trailers and car carriers). Smaller trailers may not contain trailer brakes (for example, basic 4 x utility trailers). It is recommended that, if the total trailer weight is over a couple thousand kilograms, the trailer have some sort of braking system, and the tow vehicle be equipped with a brake controller.

Types

There are different types of brake controllers currently or previously on the market.